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Can I add more panels to my existing solar energy system?

February 25, 2024
Brian Church
The words "Add more solar panels?" over an image of a solar installer adding more solar panels to a roof with existing solar modules.
In this article
Adding Solar Panels To An Existing System FAQ
Final Thoughts On Adding Solar Panels To Existing Systems

Whether you can (or should) add more solar panels to your existing solar energy system depends on many factors, including the willingness and availability of your original solar installer to perform the job. 

In many cases, solar companies will shy away from expanding existing solar energy systems that another company installed. Even at Palmetto, we can sometimes expand an existing system, but it’s not as straightforward as you might imagine.

This article will answer the most frequently asked questions about adding solar panels to existing home solar energy systems. 

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Adding Solar Panels To An Existing System FAQ

Is it easy to add more panels later if I install solar now? 

If you are interested in solar but don’t want to dive into the deep end immediately, it is logical to think, “Hey, why don’t I just buy a few solar panels now and then add more later.”  Unfortunately, it’s not as simple as that. 

In reality, building a solar energy system is generally not a piecemeal process, like gradually building up the inventory of tools and hardware in your garage. Instead, most solar energy systems are designed uniquely to fit a specific function, and adding more panels later can create a waterfall effect in which the extra power produced will impact other system components. 

For instance, adding more capacity means you may need to rewire your existing panels or upgrade the inverter from your original installation – if you have the room on your roof or property to accommodate the new panels in direct sunlight. String inverters are designed to accommodate a specific number of panels, so you can’t just add more solar panels without adding additional inverter capacity. On top of this, adding more solar panels to your solar power system will also send you back through the permitting process – putting yet another line item on your project sheet.

With expenses for the new panels, upgraded equipment, labor, and permitting, the costs of a few extra solar panels often outweigh the financial benefits of the added solar generation. Knowing this, many installers, like Palmetto, recommend designing your solar energy system to meet your home's entire electricity needs during your initial installation.   

Learn more: The Palmetto Solar Installation Process

However, there are still instances in which you may be able to add solar panels to an existing system later if you find that it is financially worth it, such as after a dramatic increase in your home’s electricity demand from buying an electric vehicle.

How much does it cost to add solar panels to an existing system?

As you can imagine, the cost of adding solar panels to an existing system increases with each additional panel you decide to install. While solar panels retail for a few hundred dollars each, remember that you will also incur costs for the extra wiring, racking, permits, and other necessary upgrades. 

Learn more: How much do solar panels cost?

All in all, adding a few extra solar panels could cost anywhere between $2,000 and $20,000 (or more!) - depending on what upgrades are required. Your unique project costs and new design capabilities may also vary depending on whether your solar installation uses individual microinverters or a central inverter system.   

Learn more: Microinverters vs String Inverters

Does adding solar panels to an existing system earn a tax credit?

Although circumstances vary, yes. In general, the costs of adding solar panels to an existing system can qualify for available incentives such as the federal solar tax credit. 

According to an IRS rule, “Earlier installations of qualifying property do not affect the availability of the credit for qualifying property in later years.” In other words - even though you already took advantage of the residential solar tax credit, that doesn’t mean you can’t take it for another spin around the block later on down the road. That said, we advise consulting a tax professional to determine if your specific upgrade will qualify.

Learn more: Everything you need to know about the solar tax credit.

Is adding solar panels to an existing system worth it?

If you are not producing enough solar energy to meet your home’s power demand, adding solar panels may be worth it if they can lower your remaining electricity bills from the utility company and pay for themselves over time. This is a common scenario that Palmetto often sees, where a customer with an older system comes to us to expand their system but still wants to keep the older system active to generate whatever power it can. This is often accomplished by adding the new system alongside the existing system so that both work together to help power the home. Today, many solar customers consider solar expansions after electrifying their homes or vehicles and consuming significantly more annual power.

Learn more: Is solar a good investment?

Can you add a solar battery storage to an existing solar panel system? 

In most instances, yes. You can add a solar battery to an existing solar panel system. While we have illustrated all the challenges that installing a few extra solar panels can bring, adding a solar battery is generally less involved. However, an inverter upgrade may still be necessary, and you may need additional permits and other approvals. Adding a solar battery allows you to store and use more of your solar energy at home rather than exporting all excess production to the energy grid. 

Learn more: How does a solar battery work?

Final Thoughts On Adding Solar Panels To Existing Systems

Ultimately, knowing whether you can add more solar panels to your system later is important to consider before you finalize your installation plans. In fact, asking whether you will be able to add solar panels to an existing system is one of our top 20 questions to ask your solar installer

Instead of adding extra solar panels, you can maximize your existing solar savings by reducing energy consumption and making your home more energy-efficient. Beyond habits like turning off your lights and unplugging vampire energy electronics, you may be able to offset more of your home’s energy use with efficient appliance upgrades or improvements to your building envelope.

As your partner in home solar, Palmetto’s experts can help you design a home solar system that will effectively use your roof space to create a cost-saving solution. We can also discuss whether or not we’re able to help add panels to your existing system. Always available to those who need us, new and current customers are welcome to reach out and contact Palmetto anytime with all renewable energy questions.

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